To compare the safety/tolerability and efficacy of a 14-day course of clarithromycin extended-release tablets (2 x 500 mg QD) with that of a 14-day course of amoxicillin-clavulanate tablets (875/125 mg BID) for the treatment of ambulatory subjects with Acute Bacterial Sinusitis (ABS).

Inclusion Criteria:

• The female must be non-lactating and at no risk for pregnancy.

• Subject must have a diagnosis of ABS. The diagnosis must be based on the following:

  • A sinus radiograph (Water's view) or CT scan with evidence of maxillary opacification or
  • Air/fluid levels purulent discharge from the nose
  • At least two of the following additional signs and symptoms lasting longer than seven days prior to and no longer than 28 days before Evaluation 1.
  • A pre-treatment sample from a sinus puncture or
  • Middle meatus endoscopy must be obtained for bacterial aerobic culture
  • Susceptibility testing (applicable only for selected investigative sites).

• Subject must be a suitable candidate for oral antibiotic therapy and able to swallow tablets intact.

Exclusion Criteria:

• A medical history of hypersensitivity or allergic reactions to clarithromycin, erythromycin, amoxicillin/clavulanate, any penicillin or any of the macrolide antibiotics.

• History of amoxicillin-clavulanate associated cholestatic jaundicehepatic dysfunction.

• Females who are pregnant or lactating.

• Subject has either of the following:

  • Chronic sinusitis (signs and symptoms lasting longer than 28 days immediately prior to Evaluation 1)
  • Significant anatomical abnormalities of the sinuses any other infection or
  • Condition which necessitates use of a concomitant systemic antibiotic.

• Evidence of uncontrolled clinically significant cardiovascular, pulmonary, metabolic, gastrointestinal, neurological, psychiatric or endocrine disease, malignancy, or other abnormality (other than the disease being studied).

• Any underlying condition/disease, that would be likely to interfere with the completion of the course of study drug therapy or follow-up.

• Known significant renal or hepatic impairment (or disease).

• Subject who has taken: a systemic antibiotic within 2 weeks before study drug administration or a long-acting injectable antibiotic (e.g., penicillin G benzathine) within 4 weeks before study drug administration.

• Immunocompromised subjects (e.g., neutropenic subjects).

• Subjects with known HIV infection.

• Treatment with any other investigational drug within 4 weeks prior to study drug administration.